A variety of packages, including dispensing packages or containers, have been developed for personal care products such as shampoo, lotion, etc., as well as for other materials. Such containers typically have a neck defining an open upper end on which is mounted a dispensing closure.
One type of dispensing closure for these kinds of containers has a flexible, pressure-openable, self-sealing, slit-type dispensing valve mounted in the closure over the container opening. When the container is squeezed, the valve slits open, and the fluid contents of the container are discharged through the open slits of the valve. The valve automatically closes to shut off fluid flow therethrough upon removal of the increased pressure--even if the container is inverted so that the valve is subjected to the weight of the contents within the container.
Designs of closures using such valves are illustrated in the U.S. Pat. Nos. 5,271,531 and 5,033,655. Typically, the closure includes a body mounted on the container neck to hold the valve over the container opening.
A lid can be provided for covering the valve during shipping and when the container is otherwise not in use. See, for example, FIGS. 31-34 of U.S. Pat. No. 5,271,531. Such a lid can be designed to prevent leakage from the valve under certain conditions. The lid can also keep dust and dirt from the valve and/or can protect the valve from damage.
In some designs for closures incorporating a flexible, pressure-openable, self-sealing, slit-type dispensing valve, the valve is retained within a closure body by means of a separate retainer piece which is snap-fit into the closure body to engage one side of a peripheral flange of the valve and clamp the valve flange against the closure body. Such snap-fit retention systems typically employ an undercut configuration on the closure body and/or retainer piece to provide the snap-fit engagement. While such undercut configurations generally function satisfactorily, it would be desirable to provide an improved system for securing the valve.
In particular, it would be desirable to provide a valve retention system that would be robust enough to better withstand loads imposed during the manufacture and assembly of the components. Such an improved system should preferably accommodate tolerances and variations in the component dimensions and also accommodate slight misalignments of the components during assembly.
Advantageously, such an improved system should also accommodate molding of the components from a variety of thermoplastic materials in a way that will tolerate some amount of manufacturing process imperfections, including molding cavitation.
Further, such an improved system should also preferably accommodate the application of torque as well as other loads that may be imposed during the use of the completed product or during the manufacture and assembly of the product.
Such an improved system should also accommodate dispensing structure designs which permit incorporation of the dispensing structure as a unitary part, or extension, of the container and which also accommodate designs that separately mount the dispensing structure on the container in a secure manner.
Further, it would be desirable if such an improved system could be provided in a dispensing structure that would accommodate efficient, high-quality, large volume manufacturing techniques with a reduced product reject rate.
Preferably, the improved dispensing structure should also accommodate high-speed manufacturing techniques that produce products having consistent operating characteristics unit-to-unit with high reliability.
The present invention provides an improved valve retention system and dispensing structure which can accommodate designs having the above-discussed benefits and features.